1. Field of the Invention
The present invention relates to the preparation of linear saturated diesters by the carbonylation of .alpha.,.beta.-unsaturated ester(s), i.e., by the reaction of carbon monoxide and an alcohol with said unsaturated ester(s).
The process according to the present invention is especially adapted for the preparation of alkyl adipates by the carbonylation of alkyl pent-2-enoates.
2. Description of the Prior Art
It is well known to this art, from Bulletin of the Chemical Society of Japan, Volume 46, pages 526 and 527 (1973), that a mixture containing dialkyl esters and, in particular, an alkyl adipate, is obtained by reacting carbon monoxide and an alcohol with an alkyl pent-3-enoate under high pressure and at elevated temperature, in the presence of cobalt carbonyl and an aromatic heterocyclic nitrogen-containing base. However, the industrial-scale application or development of a technique of this type, the value of which is not contested in principle, is seriously limited because of the lack of efficiency thereof.